This research investigates how in vitro digestion contributes to the release of antioxidant peptides crypted in soybean β-conglycinin (7S) and its deglycosylated form (D7S). It also investigates the uptake of the bioactive peptides by human intestinal Caco-2 cells using a bicameral system, and their effect on the antioxidant cell defense. Phytochemomics is used as a tool for achieving this goal. The peptides are obtained by mimicking human physiological gastrointestinal digestion conditions. The antioxidant capacity of the peptides is tested by ABTS•(+) radical cation decolorization (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)) and oxygen radical absorbance capacity assays. The antioxidant power of the peptides recovered from the basolateral chamber is also evaluated by an analysis of biomarkers of cellular oxidative stress such as cell proliferation, alkaline phosphatase, and secretion of nitric oxide, lipid peroxidation, superoxide dismutase and catalase. Peptides from D7S were more active than those of 7S in the modulation of the cell proliferation, oxidative status and differentiation of Caco-2 cells treated with H2 O2 . Differences in the bioactivity of the peptides of both proteins can be explained by analysis of the structural data obtained by mass spectrophotometry. Our findings support the bioavailability of antioxidant peptides of 7S. The antioxidant properties of 7S soy protein were influenced by events such as glycosylation, digestion, and absorption. Deglycosylation seems to be an innovative strategy for improving the properties of 7S. Deglycosylation might enhance 7S antioxidant power and reduce its immunoreactivity. The combined use of advanced analytical techniques and biochemical analyses (phytochemomics) has been a key part of this study.
Keywords: Antioxidant peptides; Bioavailability; Gastrointestinal in vitro digestion; Glycosylation; Phytochemomics.
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